basalt-26.3: roachtest: cluster_creation failed

roachtest.cluster_creation [failed](https://teamcity.cockroachdb.com/buildConfiguration/Cockroach_Nightlies_Roachtests_RoachtestNightlyGcePrivateBazel/21516791?buildTab=log) with [artifacts](https://teamcity.cockroachdb.com/buildConfiguration/Cockroach_Nightlies_Roachtests_RoachtestNightlyGcePrivateBazel/21516791?buildTab=artifacts#/rebalance/by-load/replicas/mixed-version) on basalt-26.3 @ [ff08b7555b39cd48a80fffeb988204d855ac8be3](https://github.com/cockroachdb/cockroach/commits/ff08b7555b39cd48a80fffeb988204d855ac8be3):

```
test rebalance/by-load/replicas/mixed-version failed: (test_runner.go:1087).func4: in provider: gce: BulkInsert failed for us-east1: BulkInsert operation failed for region us-east1: gce create failed due to capacity in zone(s) [us-east1-b]: grpc: SERVICE UNAVAILABLE: errors:{code:"VM_MIN_COUNT_NOT_REACHED" message:"Requested minimum count of 7 VMs could not be created."} errors:{code:"ZONE_RESOURCE_POOL_EXHAUSTED_WITH_DETAILS" error_details:{help:{links:{description:"Troubleshooting documentation" url:"https://cloud.google.com/compute/docs/resource-error"}}} error_details:{localized_message:{locale:"en-US" message:"A c4a-standard-4-lssd VM instance with 1 local SSD(s) is currently unavailable in the us-east1-b zone. Alternatively, you can try your request again with a different VM hardware configuration or at a later time. For more information, see the troubleshooting documentation."}} error_details:{error_info:{domain:"compute.googleapis.com" metadatas:{key:"attachment" value:"local-ssd:1"} metadatas:{key:"vmType" value:"c4a-standard-4-lssd"} metadatas:{key:"zone" value:"us-east1-b"} metadatas:{key:"zonesAvailable" value:""} reason:"resource_availability"}} message:"The zone 'projects/crl-e2e-infra/zones/us-east1-b' does not have enough resources available to fulfill the request. 'NULL:0/NULL:0/NULL:0 (state:STOCKOUT, sub-state:STOCKOUT, resource type:compute)'."} [code 2/Unknown] [owner=test-eng]
```

Parameters:
- cloud=gce
- coverageBuild=false
- cpu=4
- diskCount=0
- runtimeAssertionsBuild=false
Help

See: [roachtest README](https://github.com/cockroachdb/cockroach/blob/master/pkg/cmd/roachtest/README.md)

See: [How To Investigate \(internal\)](https://cockroachlabs.atlassian.net/l/c/SSSBr8c7)

/cc @cockroachlabs/test-eng

[This test on roachdash](https://roachdash.crdb.dev/?filter=status:open%20t:.*cluster_creation.*&sort=title+created&display=lastcommented+project) | [Improve this report!](https://github.com/cockroachdb/cockroach/tree/master/pkg/cmd/bazci/githubpost/issues)

Jira issue: CRDB-68429

Start with the linked TeamCity build and artifacts for roachtest cluster_creation, then inspect the failure at test_runner.go:1087 and the roachtest README. Determine whether the us-east1-b capacity error is environmental or requires a change to the test or infrastructure, and confirm the failure no longer occurs or is handled appropriately.

Written by the indexing model from the issue text.